CVE-2021-47241

Summary

In the Linux kernel, the following vulnerability has been resolved:

ethtool: strset: fix message length calculation

Outer nest for ETHTOOL_A_STRSET_STRINGSETS is not accounted for. This may result in ETHTOOL_MSG_STRSET_GET producing a warning like:

calculated message payload length (684) not sufficient
WARNING: CPU: 0 PID: 30967 at net/ethtool/netlink.c:369 ethnl_default_doit+0x87a/0xa20

and a splat.

As usually with such warnings three conditions must be met for the warning to trigger:

  • there must be no skb size rounding up (e.g. reply_size of 684);
  • string set must be per-device (so that the header gets populated);
  • the device name must be at least 12 characters long.

all in all with current user space it looks like reading priv flags is the only place this could potentially happen. Or with syzbot :)

Affected Software

VendorProductVersion RangeStatus
LinuxLinux71921690f9745fef60a2bad425f30adf8cdc9da0 < fb3a948143688e14e2cfd2a2812877923d0e5e92affected
LinuxLinux71921690f9745fef60a2bad425f30adf8cdc9da0 < cfc7f0e70d649e6d2233fba0d9390b525677d971affected
LinuxLinux71921690f9745fef60a2bad425f30adf8cdc9da0 < e175aef902697826d344ce3a12189329848fe898affected
LinuxLinux5.6affected
LinuxLinux0 < 5.6unaffected
LinuxLinux5.10.46 <= 5.10.*unaffected
LinuxLinux5.12.13 <= 5.12.*unaffected
LinuxLinux5.13 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

CVE Program Container

Additional References

References